objective: to characterize tobacco use according to level of poverty in a random, nationally representative sample of adolescents (10 to 21 years old), living in urban areas with less than 50 000 inhabitants. the study was done in 2001 as part of the baseline assessment of the evaluation of the governmental program, oportunidades. material and methods: a questionnaire was applied to 29 548 adolescents living in 30 000 selected households and it included specific questions on individual tobacco use among other questions. results: the prevalence of smokers was 3.5% (95% ci: 3.3%-3.7%) and experimenters 9.9% (95% ci: 9.6%-10.2%). a logistic regression model for clustered data was constructed in order to evaluate the associated factors that distinguish a smoker from an experimenter. after adjusting for level of poverty of the household and use of alcohol and drugs, a significant association (or = 1.5, p <0.01) was found with having a paid job and a differential association was found between gender and age group. conclusions: the results of this study suggest that the additional availability of money that an adolescent has, could increase the prevalence of tobacco smoking and that the program oportunidades should include prevention campaigns directed specifically at this population group.